Prevalence of Methicillin-Resistant Staphylococci in Dogs

The aim of the study was to investigate the occurence and species distribution of methicillin resistant staphylococci (MRS) in the nasal cavity of dogs. Nasal swabs were collected from 162 dogs entering private veterinary clinics in Hatay. Methicillin resistance was detected onto mannitol salt agar containing 2 μg/ml oxacillin and confirmed by mecA Polymerase Chain Reaction (PCR). Bacterial identification was done using 16S rRNA sequencing. Staphylococcal cassette chromosome mec (SCCmec) typing of these isolates were determined by multiplex PCR. Antimicrobial susceptibility testing were performed disk diffusion method and antimicrobial resistance genes were determined by PCR. Methicillin-resistant coagulase negative staphylococci (MRCNS) harbouring mecA were isolated from 15.4% (25/162) of dogs. The species identified were S. epidermidis (n=12), S. lentus (n=6), S. hominis (n=4), S. warneri (n=1), S. arlettae (n=1) and S. haemolyticus (n=1). mecA-mediated methicillin resistance in S. arlettae was described for the first time. Methicillin resistant Staphylococcus aureus (MRSA) and methicillin resistant Staphylococcus pseudintermedius (MRSP) were not detected. SCCmec type I, II, III and IV were identified in 1, 10, 9 and 5 MRS isolates, respectively. The results indicate that continuous surveillance is necessary to determine the emergence of MRS including MRSA.